The present invention relates to an arrangement for filtering a liquid and separating gases from the liquid.
Arrangements of the above mentioned general type are known in the art. In a known arrangement, filtering takes place during passage of the liquid through at least one wettable gas-impermeable microporous layer arranged in a ventilated housing, and the separation of gases and ventilation of the housing is performed via a liquid-repelling (liquid-impermeable) gas-permeable microporous ventilating element. The arrangement has a first chamber with an inlet opening for a liquid to be filtered, and a second chamber with an outlet opening for a filtered liquid, wherein the wettable gas-impermeable microporous layer is formed as a partition between the two chambers. Such a filter is disclosed, for example, in U.S. Pat. No. 4,265,762. The filtering in this filter takes place via a flat membrane, and the ventilation takes place via ventilating openings in the peripheral wall of the housing, which is covered by balls or flat material pieces of a hydrophobic material. The U.S. Pat. No. 3,013,072 discloses a dropping container with a hydrophilic filter element between the inlet opening and the outlet opening. Air is separated from the liquid to be filtered by a hydrophilic filter element and escapes into the surrounding atmosphere.
U.S. Pat. No. 4,190,426 shows a liquid filter in which the filtering is carried out via a flat membrane, and the aeration is performed via a liquid-repelling microporous membrane.
The above described filters possess the following disadvantages:
The ventilation in these filters takes place only when they have devices for ventilation extending upwardly, so that during operation of this filter they must also be placed in a proper position. The ventilating devices are technically expensive and in part very complicated, so that the manufacturing cost for this filter is very high. The cost factor plays a considerable role, since such filters can or must be frequently used only once. Finally, in these filters the filtering direction is fixed, so that the ventilating devices are arranged there only before the filter membranes.
Finally. U.S. Pat. No. 4,267,053 discloses a filter for solutions to be administered intravenously, in which the filter layer is formed by at least one porous hollow fiber. The hollow fiber is closed at one end and embedded with its other open end in a sealing compound block which is connected in liquid-tight manner with the peripheral wall of the housing. This known filter, however, does not have a device for separating of gases from the liquid or ventilating chamber at the liquid inlet side or the liquid outlet side.